Wekk saud, Don't be shy about the competition. To excell at this game, most are extemely competitive and strive for all the competiotion they can get.
Learning how to practice is just one small step in this game. Learning how to play when the heat is on is or often something totally different for many. Practice, practice, and paractice even more when not in action or playing someone. You have to want it and want it very badly to get to the level you want. Stay focused and constantly push yourself and as he said, don't shy from competition. It will only sharpen you more and more. Learning to practice is one thing, but it takes some many years to learn to play like they practice or vice versa.
If you are a great practice player, but tighten up in competition, this can cause many hurdles and often serious head trips which can be hard to overcome. If you practice with that long loose stroke, you had better learn to play that way. Why a play a different style than what you practice.
Are leagues a good avenue? I don't know! I'm not a fan of them, but, many are. It's too long between games and a person doesn't learn much by sitting and watching hour after hour and especially those who don't play very well anyway.
I guess that what I suggest is simple: If you want to take this game to the next few levels, you have to want it and want it badly. You have to live it day in and day out and dall the books DVD'S or instructions aren"t goiing to be of much value until you make up your mind you want it badly and will pay the price.
Play like you practice,,,or,,,,, Practice like you play. Get an attitude about it and start knocking em down!!!